On Bridge’s claim that Braun’s “trucking company and distribution companies ‘overworked and underpaid employees,'” PolitiFact turned to Kate Bronfenbrenner, a “director of labor education research at Cornell University.”

“The larger the company, the more unforgivable it is that they didn’t pay their workers,” Bronfenbrenner said. “They should have a good computer system that makes it so that everyone gets their pay.”

What PolitiFact didn’t disclose is that Bronfenbrenner is a frequent donor to Democrats and liberals, including at least nine small donations to Sen. Bernie Sanders (I-VT) in 2015 and 2016 and six donations to Barack Obama in 2008 and 2012.

A quick Google search found PolitiFact has used Bronfenbrenner as a source at least five other times on labor matters since 2011, without disclosing prior donations she made.

As a professor of labor education research, Bronfenbrenner does, indeed, seem qualified to speak on business and labor practices. But the lack of a disclosure of Bronfenbrenner’s partisan leanings begs the question: how many political donors is PolitiFact using as sources in their fact checks?